Antibiotics are a class of chemical substances produced by certain microorganisms in the course of their lives or artificially synthesized or semi-synthesized, capable of inhibiting or killing certain other microorganisms or inhibiting cell reproduction. Antibacterial drugs belong to the category of antibiotics, antibacterial drugs in the clinical mechanism of action is divided into four major categories: 1, to prevent the synthesis of the bacterial cell wall, resulting in bacterial lysis and rupture and death in a low-permeability environment, this drug is mainly penicillin and β-lactam, vancomycin, etc.; 2, the action of the cell membrane so that the increase in permeability, the cellular efflux of useful substances so that the bacterial death of bacteria, such as polymyxin and bacillus peptide; 3, on the Cells have a repair effect, inhibit protein synthesis and transcription, resulting in bacteria essential structural proteins and enzymes can not be synthesized and death, this class of drugs such as aminoglycosides and chloramphenicol, etc.; 4, inhibition of the synthesis of macromolecules in bacteria, belonging to the range of bacterial inhibition to prevent their reproduction, such as macrolides and sulfonamides, the use of all antibiotics should be based on the different parts of the site of infection and the different infected bacteria, the selection of the early, reasonable, adequate amount of antibiotics. All antibiotics should be used according to the different parts of the infection and different bacteria, and should be selected early, reasonable and sufficient amount of antibiotics, and should be used for a sufficient course of treatment. Moreover, the development of new antibiotics is very difficult, so antibiotics must be used reasonably under the guidance of physicians, so as to avoid the terrible situation of having no medication available for infections in the future due to irrational use of antibiotics.